This list of plesiosaur type specimens is a list of fossils serving as the official standard-bearers for inclusion in the species and genera of the reptile clade Plesiosauria, which includes the short-necked pliosaurs and long necked plesiosauroids. Type specimens are those which are definitionally members of biological taxa and additional specimens can only be "referred" to these taxa if an expert deems them sufficiently similar to the type.
| Species | Genus | Nickname | Catalogue number | Institution | Age | Unit | Country | Notes | Images |
|---|---|---|---|---|---|---|---|---|---|
| Dolichorhynchops osborni | Dolichorhynchops | N/A | KUVP 1300 | ||||||
| Elasmosaurus platyurus | Elasmosaurus | N/A | ANSP 10081 "(not ANSP 18001 as reported by Welles)" -Kenneth Carpenter | ||||||
| Libonectes morgani | Libonectes | N/A | SMUSMP 69120 | ||||||
| Plesiosaurus brachypterygius | N/A | N/A | GPIT von Huene 1923, pls 1–2 | ||||||
| Plesiosaurus dolichodeirus | Plesiosaurus | N/A | BMNH 22656 | United Kingdom | |||||
| Plesiosaurus guilelmiimperatoris | N/A | N/A | MB. 1893/94.1961 [Holotype] O | ||||||
| Plesiosaurus macromus | N/A | N/A | OXFUM J.28587 | ||||||
| Seeleyosaurus holzmadensis | N/A | SMNS 12039 | |||||||
http://plesiosauria.com/final_thesis/10_appendices.pdf